I have one but also don't take on builders cleans so have not had reason to use it.
However, it is not just builders debris that can be a problem.
Google 'Fabrication debris' and see what you get. When tempered glass is made if it is poorly made you can get tiny particles on the glass. If you ever use a scraper to, for example, remove bird muck there is the possibility of dislodging the debris and 'scratching' the glass with the dislodged debris.
I know I did it to 4 panes of 6'x5' patio doors!!
Also check your public liability insurance because most have a clause which says you are not covered 'for the window/glass/property you are working on.
The reason for this is because of the possible vast expence that a large claim could incure.